A resurgent Reds' side travel to the Madejski Stadium to meet a Reading outfit beaten 3-0 at Huddersfield in midweek.
Cox did not play a part in that match but is aiming for a recall to meet his former club, as is Chris Gunter although Jamie Mackie is not eligible to play.
Speaking of his time at the City Ground, Cox said: "They’re all good mates there, we had a good team spirit.
"Chris Cohen and Henri Lansbury are two of my best mates but as soon as Saturday comes they’re not, they’re your opponents."
Forest manager Dougie Freedman, meanwhile, insists he has no new injury problems following the midweek win over Bournemouth, despite being forced into several substitutions on Wednesday night.
Michail Antonio, Chris Burke and Danny Fox all looked to be struggling against the Cherries but Freedman believes the players were simply exhausted after a huge effort to keep the visitors at bay.